1. Field of the Invention
This invention is in the field of electric current generating cells and materials for the manufacture thereof and more particularly relates to cells which are made of foamed material and have radiating material circulating therein to ionize a material in the cell to activate photovoltaic portions of the cell to produce electric currents.
2. History of the Prior Art
U.S. Pat. No. 3,497,392 to J. B. Walker shows an electric current generating cell including radioactive material which "cell has a sealed case in which there is a photoelectric core that is sensitive to ultraviolet radiations. This core is provided with a multiplicity of cavities communicating with the outside of it and preferably interconnecting with one another, whereby to provide the core with a very large surface area in relation to its size. The case also contains an ionizable fluid that surrounds the photoelectric core and fills its cavities. This fluid is such that it produces ultraviolet radiation when ionized...The fluid is ionized by the radiations of. . . radioactive material. . . The resulting ultraviolet radiations activate the core to produce electric current. . . " To create the "multiplicity of cavities", Walker used a plurality of coated balls packed together with the spaces therebetween as the cavities. Unfortunately, the majority of the space which was taken up by the solid mass of the balls was useless in this cell. U.S. Pat. No. 3,956,195 to Topchiashvili et al discloses a foamed semiconductor composition which is in the form of a generally closed-cellular foam through which no interactive materials could effectively circulate.
Applicant's inventions in this field include U.S. Pat. No. 4,628,143 for a Foamed Nuclear Cell which utilizes an open-cellular foam excited to produce electricity by material entered into the interstices of the foamed structure. Applicant also has utilized foamed cellular material in U.S. Pat. Nos. 4,626,612; 4,676,966; and 4,681,981 relating to foamed thermocouple structures.